NASA Facts National Aeronautics and Space Administration Dryden Flight Research Center P.O. Box 273 Edwards, California 93523 Voice 661-276-3449 FAX 661-276-3566
[email protected] FS-2003-06-081 DFRC X-5 NASA Photo E-648. X-5 on ramp. The Bell X-5 was built to test the feasibility of changing the sweep angle of an aircraft's wings in flight. This had advantages from both an operational and research point of view. An operational aircraft could take off with its wings fully extended, reducing both its take off speed and the length of the runway needed. Once in the air, the wings could be swept back, reducing drag and increasing the aircraft's speed. For an experimental aircraft, the ability to vary the wing's sweep angle would greatly expand the research possibilities. Existing swept wing experimental aircraft, such as the D-558-II, XF-92A, X-2 and X-4, could each provide aeronautical data at only a single wing angle. A variable swept wing aircraft would be equivalent to a series of such experimental air- craft, as it could change the wing angle to the desired research objectives. Although the NACA conducted independent wind tunnel research on variable sweep wings in 1945, the X-5 originated with the Messerschmitt P.1101 experimental aircraft. This was a small jet with wings that could be adjusted on the ground to three fixed angles between 35 and 45 degrees. The P.1101 had not flown before it was captured by U.S. troops in April 1945.